A number of diseases can proliferate and be spread by animal and human faecal matter. Many of these are bacterial including diarrhoeal diseases or worms such as Helminthes. The amount of viable agents in the waste can be reduced by the application of heat for a given period of time commonly called pasteurisation.

The SOWTech pasteurisation system is a passive system that harnesses sunshine to heat the tubes. The Pasteu Panel is a continuous small diameter Butyl rubber tube.

The waste liquid or digestate from the Flexigester flows into the Pasteu Panel. The panel, being made of black Butyl rubber, absorbs the heat from the sun. This then heats up the material in the tube. Pasteurisation is achieved by a combination of elevated temperature and time. The most appropriate combination is dependent on the expected pathogens. In many developing countries the most important pathogens that require deactivation are helminthes and those causing diarrhoeal diseases.

The size of the Pasteu Panel is determined by the daily amount of waste entering the system and the length of time required for the pathogen kill. The time held in the Pasteu Panel is normally two days but this can be varied if required. By utilising the suns rays no external power is necessary to heat the material in the Pasteu Panel.

When the material has been in the Pasteu Panel for the prerequisite amount of time it is removed using the manual roller pump system. The pasteurised digested is collected in a suitable receptacle and can then be used on land as a liquid fertiliser or disposed of in a suitable manner, for example, composting or in the SOWTech “Soil Donut” system.